Switch out random number generator for tests, benches, samples.

This change makes tests, benches and samples use the new SkMWCRandom PRNG. GMs will be saved for another time, as they'll require rebaselining.

R=reed@google.com, bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://chromiumcodereview.appspot.com/23653018

git-svn-id: http://skia.googlecode.com/svn/trunk@11136 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/ScalarBench.cpp b/bench/ScalarBench.cpp
index 333dd22..405d51e 100644
--- a/bench/ScalarBench.cpp
+++ b/bench/ScalarBench.cpp
@@ -56,7 +56,7 @@
 // handling NaN values is a lot slower. Anyway, this guy is just meant to put
 // reasonable values in our arrays.
 template <typename T> void init9(T array[9]) {
-    SkRandom rand;
+    SkMWCRandom rand;
     for (int i = 0; i < 9; i++) {
         array[i] = rand.nextSScalar1();
     }
@@ -102,7 +102,7 @@
 class IsFiniteScalarBench : public ScalarBench {
 public:
     IsFiniteScalarBench(void* param) : INHERITED(param, "isfinite") {
-        SkRandom rand;
+        SkMWCRandom rand;
         for (size_t i = 0; i < ARRAY_N; ++i) {
             fArray[i] = rand.nextSScalar1();
         }
@@ -141,7 +141,7 @@
 
 public:
     RectBoundsBench(void* param) : INHERITED(param) {
-        SkRandom rand;
+        SkMWCRandom rand;
         for (int i = 0; i < PTS; ++i) {
             fPts[i].fX = rand.nextSScalar1();
             fPts[i].fY = rand.nextSScalar1();